Antenna apparatus



March 13, 1951 s. 1.. BERGEY E AL ANTENNA APPARATUS 3 Sheets-Sheet 1 Filed March 22, 1946 INVENTORS STfl/VLLV L BERGEY s. L. BERGEY ET AL 2,544,648

ANTENNA APPARATUS 3 Sheets-Sheet 2 RS ERGEY /VOTT NGI/HM INVENT STKI/VLE Y L \l/YMES ,9.

' form a M i A March 13, 1951 Filed March 22, 1946 March 13; 1951 s. L. BERGEY ETAL ANTENNA APPARATUS 3 Sheets- Sheet 3 Filed March 22, 1946 NNR L/YMES A. BY

Patented Mar. 13, 1951 ANTENNA APPARATUS Stanl y L-B rsey, Hemp ead, and-IamesA- N tingham, Garden City, N. Y. assignors to The Sperry Corporation, a corporation of Delaware Application March 22, 1946, Serial No. 656,226

7 Claims. 1

The resent invention relates to directive antenna scanning systems and more particularly to scanning systems suitable for regular scanning through any of several scanning patterns.

Directive antenna scanning systems have been employed in various types of radio navigation systems, and in radar systems employed for .determination of remote object directions and .distances. Usually, the directive antenna system is provided with a motor-driving unit adapted to cause the directive axis of the antenna to be moved through a predetermined range of movement at a regular rate, the type and range of movement being fixed according to the ,type of service for which the system is intended.

Radar systems have been provided. in diverse forms for different tactical purposes. One example is a radar system for enabling .one aircraft to intercept another aircraft and .to direct its fire toward .the intercepted craft. Another .example is a radar system arranged to enable one craft such as an airplane, for example, to search for a vessel upon the ocean and to direct explosive charges toward the vessel. A radar system for the former purpose employs variable angle conical scanning, referred .to as spiral scanning, wherein the directiveca-ntenna is rotated about the longitudinal axis of the craft at :a first speed, and the angle between the antenna axis and a direction substantially parallel with the longitudinal axis .of the .craft is regularly varied between zero and a. predetermined maximum angular divergence. Byobserving the variations of the strength :of reflected signalsin relation to the variation of the antenna direction, the pilot of the interceptor aircraft may operate the craft in such a way as to aim the longitudinal axis of the craft toward the intercepted airplane, and thus to direct .fixedly mounted and forwardly aimed guns in the interceptor craft toward the intercepted airplane. A scanning system of this general type is described in detail and claimed in U. S. Patent 2,407,305 to Langstrcth et al., issued September 10, 1946, and assigned to the assignee of the present invention.

The type of radar system which has been provided for enabling a craft operator to find a vessel on the surface of the ocean-and to direct explosive charges theretoward, on the other hand, is arranged for regular oscillatory scanning of the antenna directive axis through'a substantially horizontal and substantially planar range of movement.

In View of the different individual types of directive antenna scanning systems heretofore other.

available, if a single aircraft were required to .be equipped both for enemy aircraft interception and for finding. andattacking sea-bornecraf-t, it would be necessary to provide the aircraft with two complete radar systems, or at the least, .with two complete directive antenna scanning systems for use in conjunction with interchangeable transmitter and receiver units, sinc neither .of the above types of radar antenna scanning systems is well suited ,to' serve the purposes of "the However, it is essential to the most effective employment of aircraft that the size and weight of the radio equipment.carriedltherebyLbe kept to a minimum, :inorder that the aircraft be enabled to carry sufficient armament, ammunition, and fuel for maximum effectiveness .over .a

large radius of operation;

An object of the present invention is to provide animproved directive antenna scanning system of great flexibility of application.

More specifically, it is .an;objcc.t of the present invention to provide without sacrifice .of ruggedselectable at the will of the opera or, and to arrange the direc ive antenna scanning system for maintenance of optimum scanning speed consistent with the pattern and mode .of oper i n.

It is a further object to provide an improved directive antenna scanning system wherein .the antenna directive aXiS may beoscillated about a transverse axis, which axis of oscillation either may be regularly rotated about ;a further axis concurrently with'the oscillation,.or may be fixed in a predetermined orientation :for substantially planar scanning of the directive :axis.

Yet another object is-to provide .a directiveantenna scanning system wherein ,the antenna directive axis may be regularly oscillated through a variableqangular extent at the maximum speed of oscillation .consistent with reliable performance of the system.

Theseob'jectives have been met in the present invention by the provision of a directive antenna pivotally mounted for oscillation about an axis transverse the directive axis of the antenna, through a-range .of oscillation with which iscoordinated the oscillatory period, the speed of oscillation and range thereof being made -simultaneously variable .under the control of the -opera- ,spect thereto along the axis X-X. prevent relative rotation between the outer sleeve 3 tor. Mechanism is provided for rapidly rotating the antenna and the pivotal mounting therefor about an axis of rotation transverse the axis of oscillation, or for selectively arresting the rotation and fixing the axis of oscillation in a predetermined orientation, e. g., in a substantially vertical orientation so that the antenna directive axis is swept through a substantially planar and substantially horizontal range of directions. The oscillation of the antenna is effected through reciprocal relative translation of a tubular sleeve and a member extending therethrough, and the rotation of the antenna is accomplished by ro tation of the tubular sleeve in a bearing aligned with the longitudinal axis of the craft. The angular extent and the period of the oscillation are coordinately controlled by varying the ratio of lever arms in a reciprocating linkage employed to produce the reciprocal translation between the tubular sleeve and the member extending therethrough, and by simultaneously shifting the setting of a variable speed coupling through which the linkage is driven by a motor. The member extending through the tubular sleeve is itself made hollow, to permit the efficient transfer of high-frequency radio energy therethrough.

The invention in another of its aspects relates to novel features of the instrumentalities described herein for achieving the principal objects of the invention and to novel principles employed in those instrumentalities, whether or not these features and principles are used for the said principal objects or in the said field.

A further object of the invention is to provide improved apparatus and instrumentalities embodying novelfeatures and principles, adapted for use in realizing the above objects and also adapted for use in other fields.

The above objects and features of the present invention will be better understood, and further objects will become apparent, from the following description of a preferred embodiment of the present invention, illustrated in the drawings, wherein:

. Fig. 1 is a schematic representation of the iechanical elements of an embodiment of the present invention;

Figs. 2 and 3 are longitudinal and cross-sectional views, respectively, showing constructional details of the main scanner assembly of the embodiment illustrated in Fig. 1; and

Fig. 4 is an electrical schematic diagram showing the control circuits associated with the elements in Fig. 1.

Like reference characters are used throughout the drawings to designate similar portions thereof.

InFigs. 1 and 2 there is shown a directive antenna II illustrated as comprising a para- .boloidal reflector I2. The antenna II is pivotally supported in bearings I3, I3 for oscillation therein about an axis YY transverse the axis of the paraboloid I2, which latter coincides substantialv1 with the axis of directivity of antenna II.

Bearings I3 and I3 are supported within a yoke I4 rigidly connected to an outer sleeve I6, which in turn is supported within a bearing IT for rotation about axis X-X, the axis of sleeve I6.

An inner member I8, which may itself be tubular in form, is slideably arranged within the outer tubular sleeve or member I6 for rotation therewith but for relative translation with re- In order to I6 and theinner member I8, a key 20 (Fig. 3)

rigidly connected to the yoke I4 is arranged to cooperate with an elongated slot or groove along the outer surface of inner member I3 parallel with the axi thereof. A rack formed in the end of the inner member I8 extending within yoke I4 is arranged to mesh with a spur gear I9 (Figs. 1, 2 and 3) which in turn is coupled through a shaft 2I, a pulley 22 and a belt 23 to a pulley 24 rigidly fastened to antenna II and coaxial with the Y--Y axis bearings I3 and I3. Through this chain of elements, reciprocal translation of the inner member I8 is enabled to produce and accurately control oscillatory movement of the antenna II about the axis YY. If preferred, a pair of meshed sector spur gears of equal pitch diameters, one on shaft 2I and the other on antenna II, may be used instead of pulleys 22 and 24 and belt 23.

A motor 26 (Fig. 1) coupled through a shaft 2?, a flexible coupler 28, a Worm 29 and worm gear 3|, a shaft 32, and a sprocket 33 and chain 34 is arranged to produce regular rotation of a sprocket 36 fixed to the tubular outer sleeve I5. This motor is arranged for high-speed regular rotation of yoke I4 and the antenna I I supported therein, e. g., at a speed of 1,200 revolutions per minute.

Another motor 31 is coupled through speed reduction gears 38, 39, 4| and 42 to a shaft 43 upon which are carried a large spur gear 44 and a small spur gear 46. The small-diameter gear 48 is shown meshed with a large gear 41 arranged integrally with a smaller gear 50. The unit including gears 41 and 50 is internally splined and slidably arranged on a splined shaft 48 for driving a crank pin 49. This pin 49 is coupled through a connecting rod 5I to one end of a lever arm 52. The lever arm 52 is coupled, by a pin 53 coacting in a slot thereof, to a collar 54 seated in a circumferential groove in the end of the inner member I8. The lever arm 52 is arranged to pivot about a fulcrum 56, so that rotation of the crank pin 49 causes reciprocal translatory movement of the upper end of the lever arm 52, and accordingly compels the collar 54 to impart reciprocal translation to the inner member IB along the XX axis.

The connecting pin between connecting rod 5| and the upper end of lever arm 52 is arranged to be guided in a longitudinal slot or groove parallel to the common axis of the outer sleeve I6 and the inner member I8 in a stationary guide member I34. A potentiometer I3I having a fixedly positioned stator I32 has a slider arm I33 fixed to the connecting pin which pivotally joins connecting rod 5| and the upper end of lever 52. This potentiometer may be electrically connected with a voltage source and arranged for supplying an output voltage varying precisely in accordance with the variation of the nod angle of antenna I2. Such a voltage is useful in cooperation with radar indicator apparatu or direction finder indicator apparatus, such as may be employed with the antenna II.

A further directional reference voltage for an indicator may be provided by a generator I35 coupled through spur gears I37 and I38 to the shaft 32 and hence positively coupled to the outer tubular sleeve I6 for rotation therewith. The voltage variations determined by generator I36 and the potentiometer I3I may be applied in a well known manner to directional indicator arrangements, as for example, to the deflection circuits of a cathode ray object position indicator coupled to the output circuit of a radar receiver,

Theuse of generators and potentiometers coupled to a regularly moving directive antenna for producing synchronous sweep in an indicator is illustrated in British Patents 497,147, December 9, 193-8, British Thomson-Houston Company, and 542,634, January 21, 1942, F. Rost et al.

An ultra highfrequency energy transfer sys-- tem extends through the-member [8 for enabling energy to be transferred between the antenna II and a transmitter or a receiver, or a combination of a transmitter and receiver arranged for alternate" employment of the antenna. This energy transfer system may include a wave guide 51 (Fig. 2') extending along the axis ofthe paraboloidal reflector l2 substantially to the focal point thereof. The rearmost part of wave guide 51 may be arranged for vertical polarization Whenthe axis. YY'is vertical; and the wave guide may be twisted through 90 between the rearmost point of reflector 12' and the focal region thereof, to provide for horizontal polarization in the focal region when axis Y-Y is vertical. If desired, a dipole unit 55 including one or more dipole elements extending through and supported by a vertical plate may be attached to the end of wave guide 51' at the focal region of reflector l2, the dipole elements being coupled to the Wave guide 51" and being positioned substantially at the focus of the reflector l2;

Moreover, if desired, a further dipole element 60 may be attached to wave guide 51 in an elastic retaining mount arranged to hold it oriented parallel to the dipole elements of unit 55 during mere oscillation of antenna H, but to be turned through 90 by centrifugal force, into a position of minimum interaction with the dipole elements of unit 55, when the antenna H is rap-idly rotated. Such an arrangement of a wave guide, dipole unit and shiftable further dipole element is shown and discussed at greater length and claimed in copending U. S. application Serial No. 585,825 of John E. Karlson, filed March 31, 1945.

A coaxial line 56 having its inner conductor extending through. wave guide 51' and its outer conductor ending in a junction with the wall thereof may be employed as a link to a further wave guide 58, joining wave guide 58 in a rotatable junction adjacent bearing I3- This junction is generally similar to. the junction between coaxial transmission line 55 and wave guide 51, except that the inner and outer conductors of transmission line 56 are arranged to be rotated about their common axis (which is coincident with the YY axis) relative to wave guide 58. Wave guide 58 is coupled at its opposite end to a hollow high frequency energy conductor 59 which may be a coaxial transmission line or a wave guide extending along the axis XX of rotation of the antenna system. The hollow high frequency energy conductor 59 may be directly connected to wave guide 58, and hence may be mechanically fixed to the yoke 14'. This conductor is then rotated along with the tubular outer sleeve It by the operation of the spinner motor 26. At its rearmost end, the hollow high frequency energy conductor 59 may be coupled by a further rotating joint to a stationary wave guide 6i, through which energy is transferred to or from the associated radio circuits.

In accordance with one important feature of the present invention the operator is permitted to stop the high-speed rotation of the antenna about axis X-X by the spinner motor 26', and to lock the tubular outer sleeve I6 and the yoke id in a position for alignment of the Y-Y axis of the oscillation-permitting bearingsi'3 and I 3 in a predetermined orientation, e. g;, in a substantially vertical orientation. The oscillation of" the antenna ll produced by the operation of motor 31 is continued, so that the-directive axis of the antenna H is made to sweepthrough a substantially horizontal and substantially planar zone. In order to facilitate the automatic locking of the rotatable system H, M, i=6; [8, 3'2 with axis Y--Y in a predetermined alignment, a miniature motor 63 is coupled through a high-ratio speed-reduction gear train 64- and an" overdrive clutch 66 to the worm 29. Electrical circuits illustrated in- Fig. iand hereinafter described in further detail are provided for simultaneously deenergizing motor 25 and energizing the indexing motor 63 to provide extremely slow rotation of the antenna l I about axis-X--X.

A spring-opposed torque motor electric switch unit 61 or rotary relay is energized after a predetermined time interval following the de-energization of motor 26, and the'relay 6'? thenexerts a torque tending to cause its rotor to be rotated through a predetermined angle, e; g. 30, for actuation of its switch contact elements. The rotary relay unit 61 is coupled through a spur gear 68 and a sector gear 69 to a tooth I I- arranged toengage'ina slot 'l2- in acam '13 fixed onshaft 32. When the rotary relay 6! is energized, it depresses the tooth ll against the cylindrical outer face of cam 13, until the axis Y-Y of bearings 13 and I3 arrives at a predetermined alignment, which preferably is an alignment parallel to the normally vertical axis of the craft in which the system is installed. When this alignment is reached, as indicated by thearrival of slot 12' di rectlybeneath tooth H, therotary relay torque depresses the tooth H intothe slot 12. Sufficient rotation of the relay rotor element is thereby permitted by the depression of tooth H to shift the rotary relay contactors and tode-energize the index motor 633 to which the rotary relay is electrically connected. The rotary relay unit 61 thereafter continues to apply sufiicient torque to the sector gear 59 to hold the tooth H in engagement with slot T2, so that this tooth retains theantenna system accurately indexed and positively locked against rotation about the XX axis.

When it is desired to return tothe spiral scanning mode effected by simultaneous rotation of outer sleeve I6 and translation of the inner member I8, the rotary relay 6? isde-energized, so that the tooth H is immediately Withdrawn from its locking position in the slot 12; and the spinner motor is energized, so that the rapid rotation of the antenna about the XX axis is again provided.

In order to obtain still further flexibility of modes of operation of the scanning system, apparatus is provided. for effecting simultaneous and correlated shifts in the angular range of oscillation of antenna l I about axis Y-Y and in the period of the oscillation. When the angular range of oscillation is increased, the period of the oscillation. is increased substantially proportionately; and when the angular range is decreased the period of oscillation is decreased substantially proportionately. In this way, the antenna may be oscillated at all times at the optimum speed consistent with the angular coverage provided thereby.

For this purpose, an angular range shifting motor 76 is coupled through a speed reduction gear train ll to a shaft 18' upon which is provided a spur gear 19 meshing with a sector gear 8|,

Sector gear 8| controls the position of the fulcrum pin 56 about which the lever arm 52 operates. A helical cam 82 is also provided upon the shaft I8 for driving a cam follower 83 in translation parallel to the shaft I8 and also parallel to shaft 43 through which power is transmitted to the crank 49 to impart oscillation to the antenna II. A fork 84 rigidly connected to cam follower 83 is arranged to shift the unitary pair of spur gears 41, 50 along the splined shaft 48.

When shaft I8 is in the position in which it is shown in Fig. 1, the fulcrum pin 56 is at the top of its travel, so that the ratio of the lever arms above and below the fulcrum pin is set for maximum travel of the inner member [8 and, accordingly, for maximum angular range of oscillation of the antenna I I. This maximum range of oscillation may be of the order of 130. At the same time, the larger spur gear 4'! of the gear pair 41, 50 meshes with the smaller gear 46 of the driving gears 44, 46, providing for long-period oscillation-e. g., for one oscillation cycle per 4 seconds. Upon clockwise rotation of the shaft I8 as viewed in Fig. 1, however, as produced by counterclockwise operation of the shift motor I6, the fulcrum pin 56 is caused to move from the top to the bottom of the slot 60 in the lever arm 52, and accordingly, to reduce the range of travel of the member I8. As a result, the range of oscillation of antenna II is proportionately decreased, e. g., to an angular range of the order of 30. At the same time, the fork 84 is moved toward the spur gear 19, taking the large-diameter gear 47 out of engagement with driving gear 46 and bringing gear 50 into engagement with driving gear 44, to provide a predeterminedly increased rate of rotation of shaft 48, and thus a shorter period of oscillation of antenna II.

The diametral ratios of spur gears 46 and 41, and of the alternatively coupled gears 44 and 50, may be selected for changing the period of oscillation of the antenna II about the Y-Y axis substantially in proportion to the change of the angular range of oscillation. For example, the period of oscillation may be reduced from four seconds to one second when the angular range of oscillation is reduced from 130 to 30.

A further cam follower 86 may be provided upon a further helical cam portion 87 of shaft I8 for operating a switch 88 which may be arranged as a limit stop and travel reversing switch. Switch 08 may be arranged to arrest Inc-tor I6 upon the completion of a nod angle shifting operation, and to preset suitable control circuits for subsequent operation of the motor I6 in the reverse direction to change the oscillation conditions in the opposite sense.

The electric circuit arrangements for this feature, as Well as for the choice between spiral scan and oscillatory scan about a fixed axis, are shown in Fig. 4. An electric source IOI, which may be an aircraft ignition supply battery, is grounded at one terminal to the craft framework and connected at its opposite terminal to a main scanner power switch I02. Through switch I02, power from source IOI is supplied to the nod motor 31, to circuits for determining the angular range and period of oscillation, and to further circuits arranged for either energizing the spin motor 26 to produce spiral scanning or de-energizing motor 26 and locking the antenna about the XX axis for oscillation only about a substantially vertical YY axis.

Switch I02 is connected at its output terminal directly to one terminal of motor 31, whose opposite terminal is grounded. Motor 31 with this connection is operated at all times when the main control switch is closed.

The output terminal of switch I02 is also connected to a scanning mode selector switch I03 connected in series with the coil of a scanning mode selector relay I04. When switch I03 is closed, the contact arm I06 of relay I04 completes an actuating circuit through a heavy duty relay I01, through which the antenna rotating motor 26 is then energized to provide rapid rotation of the antenna system about the X-X axis. While switch I03 is closed and relay I04 is energized, the contact arm I08 isolates the indexing circuits I08 from source IOI, so that these circuits are prevented from interfering with the rapid rotation of the antenna system. When switch I03 is opened, the heavy duty relay I0! is deenergized, and accordingly, the spin motor 26 is turned off. The return of the contact arm I06 of relay I04 to its raised position energizes time delay relay III and the indexing motor 63. The indexing motor maintains the antenna II in rotation at an extremely low speed about the XX axis, e. g., at a speed of one revolution per minute.

After a predetermined time interval for which the time delay relay III is preadjusted, the contacts of the time delay relay are closed, as by the action of heat produced by a resistance element H2 and gradually transferred to a bi-metallic contact arm II3, and the closing of this contact circuit applies the full voltage of source IOI to the main operating coil II4 of the rotary relay 6?. This causes an appreciable torque to act upon the relay rotor 68, tending to cause rotation of the rotor and to carry the movable contact element II6 of the rotary relay 6! from its quiescent raised position, wherein it is connected through relay I04 and switch I02 to the highpotential terminal of source IIlI, downward to a position in which this movable element contacts a grounded contact terminal H1. The rotary relay torque motor is prevented from turning,

- however, until cam I3 rotates to the position at which it permits engagement of the cooperating elements "II and I3 whereupon the relay rotor turns clockwise sufiiciently to connect its movable contact element II6 to terminal In, which is connected to ground. This de-energizes and short-circuits the rotor of indexing motor 63, and reduces the actuating current through the main torque coil II4 of the rotary relay 67, by the opening of the contact elements of the time delay relay I I I and the consequent connection of a high resistance holding coil H8 in series with coil H4 in the source voltage circuit. Holding coil II8 thereafter maintains the rotary relay rotor in its actuated position, until a further operation of relay I04 is executed for restoration of spiral scanning.

For changing back from suubstantially planar scanning to spiral scanning, the switch I03 is closed, de-energizing the entire indexing circuit I 08 and releasing the element 69, II from engagement with the cam 13, and energizing spin motor 26 to provide full speed rotation about the X-X axis.

Regardless of the type of scanning employed (i. e., whether the YY axis is stationary or is rapidly rotated about the XX axis), the operator of the scanning system is able by a simple switch operation to vary the angle through which the antenna is oscillated about the YY axis. For this purpose, the shift motor 16 is arranged aneaecs with; its; field; coil 1.5L continuously energized. in

a: fixed polarization during operation-of thescanning system, and. its; rotor circuit is. connected between the. movable: contact arms. of: a pair of relays I2.I; and I22- Normally, both ofitheserelays are de-energi'zed,. so that-no potential difference is appliedto-the shift. motor rotor. circuit. For example; with: the circuit. conditions illustrated. in Fig. 4;, the coil. circuit of. relay Ill is held open by switch element 8. and the.- coil circuit of. relay I22 is held open by switch I26. In order tov change the angular range of oscillation of the antenna II, e. g., from narrow rangeto wide range, the operator need only throw the blade of the sing-1e pole, double throw switch I26 to the opposite position, e. g.,. tothe right. This completes. the circuitthrough the closed one I2! of the ganged switch elements: of thecam-operated switch 88,. energizing relay I22, and producing. a resultant potential difference between the rotor terminals of motor 16. This motor then operates. through a predetermined. range of movement, suflicient to efiect the shifting of gears-41 and 50' (Fig. 1) and of the reciprocating linkage fulcrum. 5.6, whereupon switch element I21 of switch 88. is openedand the opposite. switch element I28 thereof is. simultaneously closed. The opening of switch element. I21 de-energizes the relay I22 which was energized upon the throwing of switch I26, andthe closing of switch I23 presets. the circuit through. relay I-2I for actuation. by a. further operation of switch I26.

Thus, the oscillation range shift motor 16 is arranged to be. energized only for a. relatively brief period, sufficient to effecta shift of angular range. and. period. .of oscillation of the antenna, and to provide cam operation of the switch 88 arranged to limit the extentof movement of. the shift system. and. to preset suitable circuits. for a subsequent oscillation range shift 1 in the opposite sense.v

With the circuits. shown in. Fig. 4 in conjunction with the mechanicallfeatures of the present invention illustrated in Figs. 1-3, an operator is enabled to select any of four scanningconditions, as follows:v

(1). Spiral scanning (switch I03 closed), with wide-range oscillation (the arm of switch I26 thrown to the right);

(2) Spiral scanning (switch I03 closed), with narrow-range oscillation (switch I26 thrown to the left) v (3) Substantially planar, wide-range oscillation (switch I03 open and switch I26 thrown to the right); and

(i) Substantially planar, narrow-range oscillation (switch I113 open and switch 126 thrown to the left) With any of the above four scanning; conditions, the antenna is positively driven at the maximum speed consistent withv long life and dependability of the mechanical elements. All motive power required for regularly varying the antenna aiming is transmitted through strong mechanical elements from fixedly mounted motors, so that no control circuits need be carried through moving parts of the scanner apparatus. Real flexibility of application is made available with substantially instantaneous changeability from any of the above four operating conditions to any other. The electrical efiiciency of the system is very high, since the antenna rotation motor is energized only when spiral scanning is employed, and the oscillation producing motor is fully active in all modes of operation. The

oscillation range and period shift motor and the indexing motor are, very small, and neither of these motors is employed except during a change of the scanning conditions.

Since many changes could be made in the above construction and many apparently widely diiierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Periodically moving directive antenna apparatus for operation in wide-range or narrowrange horizontal oscillatory scan or in wideangle or narrow-angle spiral. scan, comprising a directive antenna having an axis of directivity, a tubular sleeve, first bearing means carried by said tubular sleeve and supporting said directive antenna for rotation about an axis transverse the axis of said sleeve, further bearing means supporting said tubular sleeve for rotation about its axis, an inner member in said tubular sleeve translatable with respect thereto, means coupling said inner member to said. directive antenna for rotating said antenna about said transverse axis in synchronism with translation of said inner member, motive means for imparting reciprocal translation to said inner member to produceoscillation of said antenna about said transverse axis, means for shifting the period of translation from a first period to a second period and shifting the range of travel of said inner member from a first range to a second range different from said first range by a ratio substantiall proportional to the ratio of said second period to said first period, and means selectively operable to rotate said sleeve and said first bearing means rapidly about the axis of said sleeve for spiral scan and to bring said sleeve into position for substantially vertical-plane orientation of said transverse axis for substantially horizontal scan.

2. Apparatus as defined in claim 1, further including means for transferring radio energy through said inner member between said antenna and a fixed point.

3. Apparatus as defined in claim 1, wherein said inner member is tubular; said apparatus further including hollow conductor means for transferring radio energy through said inner mem ber between said antenna and a fixed point.

4. Apparatus as defined in claim 1, wherein said inner member is tubular; said apparatus further including hollow conductor means for transferring radio energy through said inner member between fixed radio apparatus and said antenna, said hollow conductor means comprising a coaxial transmission line section extending through said tubular inner member, and means coupling said coaxial line to said antenna.

5. Dual-purpose periodically moving directive antenna apparatus permitting alternative operation in planar oscillatory scan and spiral search throughout a zone bounded by a conical locus, comprising a directive antenna having an axis of directivity, a tubular outer sleeve supported for rotation about its axis, an inner member borne within said outer sleeve for movement with respect thereto, bearing means fixed to said outer sleeve for supporting said directive antenna and permitting rotation thereof about an axis transverse said outer sleeve axis and said axis of directiv'ity, means coupling said inner member to said antenna for rotating said antenna about said transverse axis according to relative movement between said outer sleeve and said inner member, means for imparting regular movement to said inner member relative to said outer sleeve for regularly varying the angular displacement between said axis of directivity and said outer sleeve axis, means for imparting regular rotation to said outer sleeve and said transverse axis bear ing means about said outer sleeve axis, normally inefiective means for arresting said outer sleeve with the transverse axis of the antenna in a predetermined position, normally inefiective means for reducing the speed of rotation of said outer sleeve and said transverse axis bearing means, and means operable to disable said regular rotation imparting means for said outer sleeve and render said arresting and speed reducing means effective.

6. Dual-purpose periodically moving directive antenna apparatus for permitting alternative operation in planar oscillatory scan and in spiral search throughout a zone bounded by a conical locus, comprising a directive antenna having an axis of directivity, a tubular outer sleeve member supported for rotation about its axis, an inner member borne within said outer sleeve member for movement with respect thereto, bear ing means supported by one of said members for supporting said directive antenna for rotation about an axis transverse said outer sleeve member axis and said axis of directivity, means coupling the other of said members to said antenna for rotating said antenna about said transverse axis according to relative movement between said outer sleeve member and said inner member, means for producing regular relative movements between said outer sleeve member and said inner member independently of 'the rotation of said bearin means supporting member for regularly varying the angular displacement between said axis of directivity and said outer sleeve member axis, means for imparting regular rotation at a first speed to the one of said members which supports said transverse axis bearing means, normally inefieotive means for arresting said transverse axis bearing means with the transverse axis of the antenna in a substantially vertical position, normally ineffective means for reducing the speed of rotation of said transverse axis bearing means, means operable to disable said regular rotation imparting means for said transverse axis bearing means and render said arresting and speed reducing means effective, and means operable by said arresting means for disabling said speed reducing means when the transverse axis of the antenna is arrested in a substantially vertical position.

7. Dual-purpose periodically moving directive antenna apparatus for permitting alternative operation in planar oscillatory scan and in spiral scan throughout a zone bounded by a conical locus, comprising a directive antenna having an axis of directivity, a tubular outer sleeve member supported for rotation about its axis, an inner member borne within said outer sleeve member for movement with respect thereto, bearing means supported by one of said members for supporting said directive antenna for rotation about an axis transverse both said outer sleeve member axis and said axis of directivity, means coupling the other of said members to said antenna for rotating said antenna about said transverse axis according to relative movement between said members, means for producing regular relative movement between said members for periodically varying the angular displacement between said axis of directivity and said outer sleeve member axis, means for imparting high-speed regular rotation to the one of said members which supports said transverse axis bearing means, whereby said directive axis is swept through a spiral scanning pattern, means for selectively reducing the speed of rotation of said one member to a very gradual rotation and applying sufiicient torque thereto to sustain said gradual rotation to enable said bearing means supporting member to be arrested upon the attainment of predetermined orientation of said transverse bearing means, a movable locking device adapted to be coupled to said bearing means supporting member for holding it locked in a position with said transverse axis bearing means in said predetermined orientation, means operative during gradual rotation of said bearing means supporting member for urging said locking device into coupled relation with said bearing means supporting member, and means responsive to the movement of said locking device into coupled relation with said bearing means supporting member for terminating the application of torque to said member upon the locking thereof with said transverse axis in said predetermined orientation, whereby the operation of the apparatus automatically may be converted from spiral scanning to mere oscillatory scanning about a predetermined axis.

STANLEY L. BERGEY. JAMES A. NOTTINGHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,032,479 Havenor July 16, 1910 2,407,305 Langstrothet al. Sept. 10, 1946 2,407,310 Lundy et a1. Sept. 10, 1946 2,410,666 Leek Nov. 5, 1946 2,410,827 Langstroth et a1. Nov. 12, 1946 2,412,867 Briggs et al. Dec. 17, 1946 2,437,275 Skene et a1. Mar. 9, 1948 

